Apparatus for recovering particles from liquids



Sept. 13, 1938. l. WALLQUIST 2,129,802

APPARATUS FOR RECOVERING PARTICLES FROM LIQUIDS Filed March 19, 1937 INVEN TOR.

[var Wall? zulsZ".

Patented Sept. 13, 1938 UNITED STATES 2,129,802 APPARATUS FOR RECOVERING PARTICLES FROM Ivar Wallquist,

Application March 19,

LIQUIDS Karlstad, Sweden 1937, Serial No. 131,972

In Sweden March 20, 1936 2 Claims.

The present invention relates to apparatus for recovering of particles from liquids, for instance fibres and other particles from so-called white water of paper mills, ground wood-pulp mills and 5 cellulose-pulp mills.

The invention has for its object to create an apparatus of this kind, which will be of simple construction, reliable in operation and which will show high efficiency in the recovering of the par- I ticles.

With this and other objects in View the invention consists in certain novel features of construction and combination of parts as hereinafter set. forth and pointed out in the claims.

One embodiment of the invention is illustrated in the accompanying drawing in which Fig. 1 shows a vertical section of the apparatus, Fig. 2 is a plan View of same with the wire cloth removed, Fig. 3 is an axial and vertical section of the cylinder and container. With reference to the drawing Ia and lb denote two vats or containers in each of which a rotary drum or cylinder 2a and 2b respectively is provided. The peripheries of the cylinders consist of coarse wire cloth, perforated plate or similar material. The ends of the cylinders are closed with the exception of a hole in the centre of one of the ends, to which a hollow shaft, 3a or 3b respectively is connected. The shafts 4a and 4b respectively of the other end of the cylinders are solid. Over the two cylinders, which are driven in some suitable manner, an endless wire cloth 5 runs which may be of a kind similar to that used in paper machines. The wire cloth runs over guide rolls, one of which, 6, also serves another purpose as will be hereinafter described, while the others, I, serve to guide the wire cloth in suitable directions so as to run free from the containers, Ia, lb. One of the containers Ia, has an inlet 8a for the g0 liquid to be purified. Said liquid passes through the cylinder 2a and the portion of the wire cloth running over same and escapes from the interior of the cylinder through the hollow shaft 3a and through the pipe or conduit 9a into the second container lb. Then the liquid passes into the second cylinder 2?) through the wire cloth running over same, and escapes from this cylinder through the hollow shaft 3?) and the pipe or con- 1 duit 9b connected to same. Suitable packings are provided between the rotating outlets 3a, 3b and. the stationary pipes 9a, 911.

On the portion of the wire cloth running'over the first cylinder 2a practically all, coarser and some of the finer particles inthe liquid settle,

55 so that an unbroken layer of particles In is formed on the continuously moving wire cloth. The liquid flowing to the second container lb, accordingly contains only finer particles. The layer of particles formed on the wire cloth on the first cylinder 2a is brought by the wire cloth onto the second cylinder 21), where the layer serves as a filter for the finer particles remaining in the liquid when passing from the container ib into the cylinder 2b. In this way a high degree of purification of the liquid is obtained. In order to accelerate the passing of the liquid from the containers into respective cylinders, an increased difference of pressure may be established between the liquid outside and inside the first or the second cylinder or both. This pressure difference may be accomplished either by a reduced pressure inside the cylinders or by an increased pressure outside them or by both. The two containers may be placed on the same level, and in this case a pump may be used to transport the liquid from the cylinder 3a to the container lb, or the two containers may be on difierent levels as shown in the drawings in which case the liquid may fiow by gravity.

When the wire cloth 5 leaves the second cylinder 2?), it passes over the guide roll ii where the layer of particles comes on the underside of the cloth. If the layer then sticks to the roll 6 rather than to the wire cloth 5, it continues on and with the surface of the roll 6. The layer may then be taken off the roll 6 by a scraper or doctor 58, after which it falls down into a chute [2 or similar means from which, after eventual dilution with water, it may be transported to the place where the recovered particles are to be used or disposed of. If the layer it] rather sticks to the underside of the wire cloth 5 than to the roll 6, it may be taken off the cloth for instance by a sprayer pipe H, and it may then fall down into and be removed through the chute I2. If a layer having a high degree of dryness is desired, the roll 6 may be pressed against the cylinder 21), whereby some of the water in the layer is pressed out.

It is evident that the liquid may also be brought to pass the wire cloth three or more times. If the liquid, for instance, has to pass three times through the wire cloth the wire cloth has to run over three cylinders and through three containers in a Way corresponding to the embodiment of Figs. 1-3.

; The details of the apparatus may vary in many ways without the principle of the invention being changed.

What I claim is:-

1. An apparatus for recovering of particles from liquids comprising an endless movable filtering cloth, a plurality of containers, a rotary pervious cylinder in each of said containers, each container having an inlet formed therein for the liquid to be treated on the outside of the cylinder and an outlet formed therein for the liquid from the interior of the cylinder, the outlet of one container being connected with the inlet of the second container, and an endless filtering cloth running over said rotary cylinders whereby a layer of particles from the liquid is formed in one container and serve as a filter for the same liquid in a second container.

2. An apparatus for recovering of particles from liquids comprising an endless movable filtering cloth, a plurality of containers, a rotary pertainer and serve as a filter for the same liquid 10 .in a second container, and a guide roll having said filtering cloth running thereover after having passed through the last container and adapted to take off the layer of particles recovered from the liquid by said filtering cloth.

IVAR WALLQUIST. 

